Short Message Service (SMS), as the name implies, is a messaging service provided by wireless cellular networks for the exchange of short digital messages between mobile devices. Sometimes referred to as text messaging, these short digital messages may be user-specific messages intended for a specific recipient mobile device or broadcast messages intended for receipt by multiple mobile devices. Often when the SMS message is received by a mobile device, the SMS message is stored for future viewing in either an internal memory or in a removable memory module, such as a smart card device.
SMS may be supported by a variety of wireless communication systems, including code division multiple access (CDMA) systems and time division multiple access (TDMA) systems. Examples of a CDMA system include, but are not limited to cdma2000, W-CDMA, and IS-95. Examples of a TDMA system include, but are not limited to GSM (Global System for Mobile Communications) and its derivatives, such as UMTS (Universal Mobile Telecommunications Systems). Such TDMA communication systems are referred to herein as non-CDMA communication systems.
The particular form of SMS protocol being implemented on a wireless communication system will depend on which communication system technology is being employed. The different SMS implementations have different capabilities and utilize different message types and formats for sending short messages. Nevertheless, while CDMA and GSM type networks may differ and support different SMS implementations, mobile devices supported by a CDMA network may send messages to a mobile device supported by a GSM network and vice versa through one or more intervening digital communication networks. Typical mobile devices are single mode, meaning that they support communication with only one type of cellular network system, and thus support only one form of SMS. A multi-mode mobile device can support communication with more than one type of cellular network system, such as communication with a CDMA network and a GSM network, and thus support more than one form of SMS.
Since GSM SMS and CDMA SMS implement different SMS message types, formats, and protocols, it may not be possible to fully translate a CDMA SMS message into a GSM SMS message without loss of some information. This is because some of the message parameters or message types available in one SMS format are not defined in the other SMS format. In particular, non-CDMA wireless mobile devices, such as GSM/UMTS cellular mobile devices, may not support the full range of message parameters which are included in a CDMA SMS message. For example, a CDMA SMS message may include parameters specifying privacy, urgency, or delay of a message, which are parameters that do not appear in a GSM SMS message. Thus, when a CDMA mobile device sends a SMS message to a GSM mobile device, the additional message parameters supported by the CDMA mobile device are lost (i.e., they are not forwarded on) when received by the GSM mobile device. If the GSM mobile device which received the SMS message from the CDMA mobile device were to forward the SMS message to another CDMA mobile device, the additional CDMA SMS parameters would continue to be absent in the SMS message sent to the second CDMA mobile device, despite the second CDMA mobile device's ability to support the lost parameters. Accordingly, a system and method are desired which preserve the additional CDMA SMS parameters when sent to a non-CDMA mobile device.